Science - USA (2019-08-30)

CREDITS: (FROM TOP) BROBEL DESIGN; WAIMEA VALLEY BOTANICAL GARDENS; YAOWU YUAN

SCIENCE sciencemag.org 30 AUGUST 2019 • VOL 365 ISSUE 6456 839

30 AUGUST 2019 • VOLUME 365 • ISSUE 6456

CONTENTS

858

Measuring manipulation:

Social media and elections

NEWS

IN BRIEF

844 News at a glance

IN DEPTH

847 ERADICATION GOAL SPLITS

MALARIA COMMUNITY

A Lancet panel wants to end the disease

by 2050. A WHO panel says that’s not

realistic By M. Enserink

848 ANCIENT SITE IN IDAHO IMPLIES

FIRST AMERICANS CAME BY SEA

16,000-year-old occupation predates

possible land route By L. Wade

▶ RESEARCH ARTICLE P. 891

849 MODIFIED CRISPR CUTS AND SPLICES

WHOLE GENOMES

New tools bring editing to synthetic

biology By R. F. Service

▶ REPORT P. 922

850 STUNNING SKULL

SHAKES HUMAN FAMILY TREE

Researchers reveal the

4-million-year-old face of the most

ancient australopithecine By M. Price

INSIGHTS

POLICY FORUM

858 PROTECTING ELECTIONS

FROM SOCIAL MEDIA MANIPULATION

Rigorous causal analysis could

help harden democracy against

future attacks By S. Aral and D. Eckles

PERSPECTIVES

862 THE IMMUNOLOGICAL CODE

OF PREGNANCY

Maternal immune cells interact

with the placenta and influence

pregnancy complications

By F. Colucci

864 AI SURPASSES HUMANS AT

SIX-PLAYER POKER

Self-learning Pluribus beats five

humans in Texas hold’em showdown

By A. Blair and A. Saffidine

▶ RESEARCH ARTICLE P. 885

865 HOW HUMANS CHANGED

THE FACE OF EARTH

Archaeological evidence shows that

anthropogenic changes began earlier

and spread faster than previously

estimated By N. Roberts

▶RESEARCH ARTICLE P. 897

866 THE MITSUNOBU REACTION,

REIMAGINED

Catalytic nucleophilic substitution

of alcohols makes organic synthesis

greener By L. Longwitz and T. Werner

▶ REPORT P. 910

868 BACTERIA SEND MESSAGES

TO COLONIZE PLANT ROOTS

Bacteria-derived RNA fragments

target host plant genes to

promote root colonization

By P. Baldrich and B. C. Meyers

▶ REPORT P. 919

869 HOW DO GENES AFFECT

SAME-SEX BEHAVIOR?

Genetic loci linked with same-sex

sexual behavior cannot predict

orientation of individuals

By M. C. Mills

▶RESEARCH ARTICLE P. 882

851 NO MICROBIOME IS AN ISLAND,

SURVEY REVEALS

Sampling in Hawaiian valley

shows wider environment shapes each

organism’s microbial community

By E. Pennisi

▶ PODCAST

852 WORLD’S OLDEST IMPACT CRATER

DATED IN AUSTRALIAN OUTBACK

The 2.2-billion-year-old

Yarrabubba impact came at the

end of a planetwide deep freeze

By E. Hand

853 AMAZON FIRES CLEARLY LINKED

TO DEFORESTATION, SCIENTISTS SAY

Brazilian government deflects

blame for rise in fire activity

By H. Escobar

F E AT U R ES

854 THE ALLURE OF

MONKEYFLOWERS

A tough, diverse,

colorful weed used

in evolutionary

studies is becoming

a key model

for plant biology

By E. Pennisi

F

d

ng

851

Published by AAAS